Belt Slip Research Articles

Modeling of Belt Friction for Simulation of Belt Slip with Stick-slip Phenomenon

Modeling of Belt Friction for Simulation of Belt Slip with Stick-slip Phenomenon

Review of latest technological advancement in electro-mechanical continuously variable transmission

Continuously variable transmission (CVT) is a type of automotive transmission commonly used to achieve minimum fuel consumption. Nevertheless, a conventional CVT applies a hydraulic actuation system, which is powered by the vehicle's engine, to vary its ratio and to clamp the metal pushing V-belt accordingly. As a result, a significant portion of the engine power is diverted for the CVT's operation, making the powertrain system significantly less efficient. To address this challenge, many researchers have proposed the idea of electro-mechanical CVT (EM CVT). This paper provides a review of the latest designs of EM CVT, followed by highlights on the relevant research areas that should be pursued so that the advances made in EM CVT can be brought closer to commercialisation. These areas are: 1) efficiency validation of an EM CVT vs. a conventional CVT; 2) durability of the screw-thread system and the thrust bearing; 3) ratio and belt slip controls; 4) packaging of the actuation system.

Verification of a method for determining the limit pressure peak in a mechanical continuously variable transmission

This research concerns the continuously variable transmission that is to be used in a hybrid drivetrain with a mechanical energy accumulator as a secondary energy source. The purpose of this research is to verify the method of determining the pressure surge which ensures a fast but safe ratio change, from the perspective of the belt slip point of a continuously variable transmission. The obtained results allowed to decide on the design of a more extensive test bench enabling simulation of the load of a continuously variable transmission resulting from the acceleration and braking of the car's mass. In addition, the test results confirmed the possibility of regulating the pressures in two actuators to change the ratio and increase the speed of this change.

The analysis of an influence of rubber V-belt physical properties on CVT efficiency

This work deals with the analysis of the CVT efficiency for three different rubber V-belts. The bench tests have been conducted on the complete light two-wheeled vehicle drive system so the experiments refer to real exploitation conditions. The research has been performed for fixed gear ratios. The overall efficiency and belt slip have been specified. The longitudinal belt velocity has been measured by the contactless measurement head. The basic belts physical properties have been estimated and significant dissimilarities of their construction details, used materials and stiffness parameters have been revealed. The explicit differences of overall efficiency and belt slip have been observed between tested belts. The V-belt features limiting specified type of losses contributes to increasing other losses at the same time. Furthermore the gear ratio essential influence on the belt slip has been noticeable. The amount of slip value indicates that this is significant part of the total power losses as it has been described by Bertini. However it clashes with the Chen research, where the slip corresponds with the marginal part of the overall losses.

Geology, geochronology, geochemical characteristics and origin of Baomai porphyry Cu (Mo) deposit, Yulong Belt, Tibet

The Baomai porphyry Cu-Mo deposit is a newly discovered deposit located in the northern section of the Yulong porphyry Cu belt, eastern Tibet. It is associated with Eocene biotite monzogranite intrusions that were emplaced into Paleoproterozoic Ningduo Group and Middle-Upper Triassic sedimentary rocks. A biotite monzogranite porphyry with a zircon U-Pb age of 42.7 Ma was intruded by several post-ore diorite porphyry dikes (ca. 37.8 Ma). Alteration mineral assemblages consistent with argillic, phyllic, and hornfels were identified in ore-bearing porphyries and host rocks at Baomai. Argillic and phyllic alteration assemblages are spatially related to high-grade Cu and Mo mineralization, whereas hornfels alteration is accompanied by weak Cu mineralization. Molybdenite from the mineralized porphyry returned a Re-Os isochron age of 42.6 Ma, and is considered to represent the age of porphyry-style mineralization at the deposit. Ore-bearing porphyries in Baomai are high-K (K2O/Na2O >1), alkaline-rich intrusions rich in LREE, LILE (e.g., Rb, U, K), depleted in HFSE (e.g., Nb, Ta, P and Ti) and contain absent or slightly negative Eu anomalies and no significant Ce anomalies. Slightly high 87Sr/86Sr ratios (0.7064–0.7076), low εNd(t) values (−2.5 to −4.6), uniform (206Pb/204Pb)i ratios (18.70–18.75) and positive εHf(t) values (0–5.3) of ore-bearing porphyries at Baomai indicate that they share the same or similar petrogenesis to other mineralized porphyries within the Yulong porphyry Cu belt. The porphyries were likely generated from partial melting of phlogopite-bearing amphibolite or amphibolite eclogite with a low degree of crystal fractionation, and related to enrichment mantle (EMII) transformed or mixed by older subducted slab-derived fluid. Actually, there are no significant three stages of ore-bearing magmatic activities in Yulong porphyry Copper belt (Hou et al., 2003b), Eocene intrusions (37–43 Ma) and regional strike slip faulting were all important factors in controlling the formation of these Cu-polymetallic deposits during the Eocene India-Tibetan collision.

FRICTIONAL PROBLEMS IN CONTINUOUSLY VARIABLE TRANSMISSION BELT DRIVES

The article describes the results of the research carried out on the evaluation of the influence of friction pairs (rubber belt – belt pulley in belt drive) on the ability to transmit power. In order to determine the characteristics of the belt drive operation, measurements were made on a real belt drive from the drive train of a light two-wheeled vehicle. The measurement was carried out in conditions of changes in the dynamic load. The measurements of the belt slip on the belt pulley within the whole range of the changes of gear ratios and angular speed of the engine were made. During the tests, belts made from various rubber mixtures were compared. The values of the friction coefficients between the surface of belts and the belt pulley were measured. Model analyses of the impact of belt slip on the wheel related to the temperature of Belt drive elements were also made. Generally, one can ascertain that, in belt drive systems, power losses are a combination of speed losses and torque losses. The increase in the efficiency of belt drives is possible by decreasing power losses. It is possible to obtain the high performance of continuously variable transmission belt drives with a V- belt solely with the proper choice of the design parameters, which is possible only after the exact recognition of the operational characteristics unique to this class of belt drive systems.

Optimal Design of an Autotensioner in an Automotive Belt Drive System Via a Dynamic Adaptive PSO-GA

Noise, vibration, and harshness performances are always concerns in design of an automotive belt drive system. The design problem of the automotive belt drive system requires the minimum transverse vibration of each belt span and minimum rotational vibrations of each pulley and the tensioner arm at the same time, with constraints on tension fluctuations in each belt span. The autotensioner is a key component to maintain belt tensions, avoid belt slip, and absorb vibrations in the automotive belt drive system. In this work, a dynamic adaptive particle swarm optimization and genetic algorithm (DAPSO-GA) is proposed to find an optimum design of an autotensioner to solve this design problem and achieve design targets. A dynamic adaptive inertia factor is introduced in the basic particle swarm optimization (PSO) algorithm to balance the convergence rate and global optimum search ability by adaptively adjusting the search velocity during the search process. genetic algorithm (GA)-related operators including a selection operator with time-varying selection probability, crossover operator, and n-point random mutation operator are incorporated in the PSO algorithm to further exploit optimal solutions generated by the PSO algorithm. These operators are used to diversify the swarm and prevent premature convergence. The objective function is established using a weighted-sum method, and the penalty function method is used to deal with constraints. Optimization on an example automotive belt drive system shows that the system vibration is greatly improved after optimization compared with that of its original design.

Statistic-Based Method to Monitor Belt Transmission Looseness Through Motor Phase Currents

Belt–pulley systems are widely used in the industry due to their high efficiency and their low cost. However, only few works exist about the monitoring of their degradation. This paper details the impact of belt looseness on electrical measurements under steady and transient state in order to identify spectral signatures. This analysis enlightens the advantage of the transient state to detect belt looseness because it exacerbates belt slip. An innovative methodology is then proposed based on the application of a square-wave speed reference in order to monitor belt looseness. A statistical-based indicator is defined from the phase currents in order to automatically detect drifting of the indicator. A normalization process is also applied to increase the detection robustness. The proposed indicator is evaluated on a 30-kW induction machine and a direct-current machine coupled with two trapezoidal belts for three speed and four load conditions. It reaches very good results with almost 90% correct detections for 1% false alarms. These results are way better than those obtained with a classic spectral analysis during the steady state. Moreover, results demonstrate that higher load conditions are more accurate for the monitoring of belt looseness.

Effect of Flat Belt Thickness on Steady-State Belt Stresses and Slip

A necessary condition for high-fidelity dynamic simulation of belt-drives is to accurately predict the belt stresses, pulley angular velocities, belt slip, and belt-drive energy efficiency. In previous papers, those quantities were predicted using thin shell, beam, or truss elements along with a Coulomb friction model. However, flat rubber belts have a finite thickness and the reinforcements are typically located near the top surface of the belt. In this paper, the effect of the belt thickness on the aforementioned response quantities is studied using a two-pulley belt-drive. The belt rubber matrix is modeled using three-dimensional brick elements. Belt reinforcements are modeled using one-dimensional truss elements at the top surface of the belt. Friction between the belt and the pulleys is modeled using an asperity-based Coulomb friction model. The pulleys are modeled as cylindrical rigid bodies. The equations of motion are integrated using a time-accurate explicit solution procedure.

Indirect Clamping Force Measurement Method Using Current Sensor for Electro-Mechanical Dual Acting Pulley Continuously Variable Transmission System

This paper introduces an electro-mechanical dual acting pulley continuously variable transmission (EMDAP CVT) system and presents a method of measuring belt-pulley clamping force indirectly using a DC motor current sensor. The EMDAP CVT mainly consists of two movable primary (input) and secondary (output) pulley sheaves connected by metal pushing V-belt. Two DC motor’s actuation systems adjust the CVT ratio. Additionally, the secondary actuation system controls belt-pulley clamping force by adjusting the flatness of the spring discs placed at the back of each secondary pulley sheave to keep the belt tight and prevent belt slip. Ideally, a force sensor is used to measure the belt-pulley clamping force however the use of force sensor inside transmission gearbox is not feasible due to high temperature and oily environment. A viable solution for indirectly measuring the clamping force using current sensor for DC motor is proposed. Since the DC motor actuates the movable pulleys to clamp the belt, the relationship between the DC motor current and belt-pulley clamping force can then be investigated experimentally. The results will give positive impact on precisely controlling belt-pulley clamping force of EMDAP CVT using current sensor which is relatively simpler and less expensive than force sensor.

A Comparison of Methods for Linear Cell-to-Cell Mapping and Application Example for Fault Detection and Isolation

In this paper, the Generalized Cell Mapping (GCM) method for a linear system is compared with a new stochastic method for novel cell-to-cell mapping. The authors presented the new stochastic method in a previous paper last year. The two methods are compared in an application example of a vehicle alternator. The alternator may experience three faults including belt slippage, a brokendiode, or incorrect controller reference voltage. Fault detection and isolation (FDI) is performed using the two cell-to-cell mapping methods. The results show that the new stochastic method is more computationally intensive but yields better isolation results than the GCM method

Intelligent Multiobjective Slip and Speed Ratio Control of a Novel Dual-Belt Continuously Variable Transmission for Automobiles

Van Doorne’s continuously variable transmission (CVT) is the most popular CVT design for automotive transmission, but it is only applicable to low-power passenger cars because of its low torque capacity. To overcome this limitation of traditional single-belt CVT, a novel dual-belt Van Doorne’s CVT (DBVCVT) system, which is applicable to heavy-duty vehicles, has been previously proposed by the authors. This paper, based on the published analytical model and test rig of DBVCVT, further proposes an intelligent multiobjective fuzzy controller for slip and speed ratio control of DBVCVT. The controller aims to safely control the clamping forces of both the primary and the secondary pulleys in order to improve the transmission efficiency, achieve the accurate speed ratio, and avoid the belt slip under different engine loads and vehicle speeds. The slip, speed ratio, and transmission efficiency dynamics of DBVCVT are firstly analyzed and modeled in this paper. With the aid of a flexible objective function, the analytical model, and fuzzy logic, a Pareto rule base for fuzzy controller is developed for multiobjective DBVCVT control. Experimental results show that the proposed controller for slip and speed ratio regulation of DBVCVT is effective and performs well under different user-defined weights.

A Stochastic Modeling Approach of Quantized Systems with Application to Fault Detection and Isolation of an Automotive Electrical Power Generation Storage System


 
 
 This paper introduces a stochastic modeling approach for a quantized system for the purpose of fault detection and isolation in an automotive alternator system. Three common alternator faults including belt slip, diode failure, and incorrect reference voltage for the voltage controller are considered and analyzed. A continuous nonlinear model of the alternator system is quantized into discrete states in order to simplify diagnostic efforts. The paper describes a stochastic modeling approach that creates a time-varying probability transition matrix that can be computed in real- time without the need for Monte Carlo simulation. Fault detection and isolation occurs through comparison of the most probable state from the transition matrix and the quantized output state.
 
 

The development of an electronic system to continually monitor, indicate and control, 'belt slippage' in industrial friction 'V' belt drive transmission systems

Belts have been used for centuries as a mechanism to transfer power from some form of drive system to a variety of load systems. Within industry today, many designs of belts but particularly friction, trapezoidal shaped 'V' belts are used and generally transfer power generated by electrical motors to numerous forms of driven load systems. It is suggested that belt systems, through their simplicity are sadly neglected by maintenance functions and generally are left unattended until high degrees of 'belt slippage' through loss of friction or 'belt breakage' provokes maintenance attention. These circumstances are most often identified through the reduced or loss of manufacturing production or the occurrence of catastrophic circumstances such as fire caused through excessive friction/ high belt slippage conditions. Obviously, these situations incur financial losses to companies and in some cases the near loss of the company's main manufacturing plant. Consequently, a satisfactory, viable solution is currently sought by industry to improve on current labour intensive maintenance practices. This paper will present an account of the development of an industrially robust, accurate and repeatable electronic system which continually monitors and indicates the degree of 'slippage' in a 'V' belt drive transmission system and in the circumstance of belt breakage or high belt slippage will enable and control the switching off the drive motor.

720 金属Vベルト式CVTの最適推力制御へ向けたベルト滑り判別手法の確立(GS-10 先端制御)

720 金属Vベルト式CVTの最適推力制御へ向けたベルト滑り判別手法の確立(GS-10 先端制御)

From transmission error measurement to pulley–belt slip determination in serpentine belt drives: Influence of tensioner and belt characteristics

Serpentine belt drives are often used in front end accessory drive of automotive engine. The accessories resistant torques are getting higher within new technological innovations as stater-alternator, and belt transmissions are always asked for higher capacity. Two kind of tensioners are used to maintain minimum tension that insure power transmission and minimize slip : dry friction or hydraulic tensioners. An experimental device and a specific transmission error measurement method have been used to evaluate the performances of a generic transmission by determining the pulley–belt slip for these two kinds of tensioner. Transmission error between pulleys, pulley/belt slip are deduced from pulley rotation angle measurements. Results obtained show that : the use of tensioner limits belt slip on pulleys, pulley–belt slip is reachable from transmission error measurement, belt non uniform characteristics are responsible of low frequency modulations of transmission error.

Shift dynamics modelling for optimisation of variator slip control in a pushbelt CVT

Efficiency improvement of the pushbelt CVT by reducing variator clamping forces is well established. The increased risk of gross belt slip calls for novel approach, including direct control of belt slip. First attempts led to promising results in steady state conditions, but unacceptable slip occurred during fast shifting events. In this work theoretical variator shift models are validated. Results are used for model optimisation of the variator shift dynamics, leading to an optimised CVT slip controller. Results of the experiments after implementation in a test vehicle are presented. A comparison is made to the results obtained with the previous controller.

Effective Control of Pulley Thrusts using an Index Describing Belt Slip State in Metal V-belt Type CVT for Improving Transmitting Efficiency

Effective Control of Pulley Thrusts using an Index Describing Belt Slip State in Metal V-belt Type CVT for Improving Transmitting Efficiency

A New THOR Shoulder Design: A Comparison with Volunteers, the Hybrid III, and THOR NT

Objective. Since the shoulders are rarely seriously injured in frontal or oblique collisions, they have been given low priority in the development of frontal impact crash test dummies. The shoulder complex geometry and its kinematics are of vital importance for the overall dummy kinematics. The shoulder complex also influences the risk of the safety belt slipping off the shoulder in oblique forward collisions. The first aim of this study was to develop a new 50th percentile male THOR shoulder design, while the second was to compare the new shoulder, mounted on a THOR NT dummy, with volunteer, THOR NT, and Hybrid III range of motion and stiffness data. The third aim was to test the repeatability of the new shoulder during dynamic testing and to see how the design behaves with respect to belt slippage in a 45° far-side collision. Methods. The new 50th percentile THOR shoulder design was developed with the aid of a shell model of the seated University of Michigan Transportation Research Institute (UMTRI) 50th percentile male with coordinates for joints and bony landmarks (Schneider et al., 1983). The new shoulder design has human-like bony landmarks for the acromion and coracoid processes. The clavicle curvature and length are also made similar to that of a male human, as is the range of motion in the anterior-posterior, superior-inferior, and medial-lateral directions. The new shoulder design was manufactured and tested under the same conditions that Törnvall et al. (2005b) used to compare the shoulder range of motion for the volunteers, Hybrid III, and THOR Alpha. The new design was also tested in two dynamic test configurations: the first was a 0° full-frontal test and the second was a 45° far-side test. The dummy tests were conducted with an R-16 seat with a three-point belt, the Δ V was 27.0 ± 0.5 km/h and the maximum peak acceleration was approximately 14.6 ± 0.5 g for each test. Results. A new shoulder design with geometry close to that of humans was developed to be retrofitted to the THOR NT dummy. The results showed that the range of motion for the new shoulder complex during static loading was larger by at least a factor of three, for the maximum load (200 N/arm), than that of either the Hybrid III or the THOR NT; this means it was more similar to the volunteers' range of motion. It was observed that the THOR NT with the new shoulder did not slide out of the shoulder belt during a far-side collision. The performance of the new shoulder was reasonably repeatable and stable during both the static tests and the sled tests. Conclusion. A new shoulder for the THOR NT has been designed and developed, and data from static range of motion tests and sled tests indicate that the new shoulder complex has the potential to function in a more human-like manner on the THOR dummy.

Control of a hydraulically actuated continuously variable transmission

Vehicular drivelines with hierarchical powertrain control require good component controller tracking, enabling the main controller to reach the desired goals. This paper focuses on the development of a transmission ratio controller for a hydraulically actuated metal push-belt continuously variable transmission (CVT), using models for the mechanical and the hydraulic part of the CVT. The controller consists of an anti-windup PID feedback part with linearizing weighting and a setpoint feedforward. Physical constraints on the system, especially with respect to the hydraulic pressures, are accounted for using a feedforward part to eliminate their undesired effects on the ratio. The total ratio controller guarantees that one clamping pressure setpoint is minimal, avoiding belt slip, while the other is raised above the minimum level to enable shifting. This approach has potential for improving the efficiency of the CVT, compared to non-model based ratio controllers. Vehicle experiments show that adequate tracking is obtained together with good robustness against actuator saturation. The largest deviations from the ratio setpoint are caused by actuator pressure saturation. It is further revealed that all feedforward and compensator terms in the controller have a beneficial effect on minimizing the tracking error.